Printing ribbon spool

ABSTRACT

A printing ribbon spool are disclosed for maintaining the original print-out density or consistency of a printing ribbon by contact between a pad on the spool and a side edge of the ribbon. Ink is communicated to the pad from a sealed reservoir by way of a wick which communicates with the reservoir through a hole substantially smaller in diameter than the normal uncompressed diameter of the wick.

United States Patent 1191 Ploeger, Jr. et al.

[ June 25, 1974 PRINTING RIBBON SPOOL 1 6116 197/171 .7 l 36 eckman 197/171 Inventors: Walter Ploeger,Jr., North Bellmore, 2,549,561 6/1952 Knight I I 19mm X p IslaniNXsJoh" 2,667,257 1/1954 Hurtado 197/175 p, Montreal, Quebec, Canada 2,724,489 11/1955 Fields 197/171 1 2,869,706 l/l959 Bishop l97/l7l Asslgneesg 3:g:: g i? g 3,241,522 3/1966 Knight 197/171 x g g g i jg f i g g f g g ggg gy Primary ExaminerRobert E. Pulfrey a l art inte'rest to each Assistant ExaminerEdward M. Coven p Attorney, Agent, or FirmSeidel, Gonda & [22] Filed: NOV. 4, 1971 Goldhammer [21] Appl. No.: 195,710 [57] ABSTRACT 52 us. 01. 197/171, 197/175 1 A Printing ribbon Spool a disclosed for maintaining [51] 1111. c1 .4 B41 j 31/14 the Original Print-Out density Consistency of a Print- [58] Field 61 Search 197/171, mg ribbon by Contact between a Pad the Spool and a side edge of the ribbon. Ink is communicated to the [56] References Cited pad from a sealed reservoir by way of a wick which UNITED STATES PATENTS communicates with the reservoir through a hole substantially smaller in diameter than the normal uncom- 849,143 4/1907 Langen l97/l71 X pressed diameteryof the wick 1,366,802 l/l92l Hodge 1 l97/l7l 1,953,881 4/1934 Hanable 'l97/l7l 10 Claims, 4 Drawing Figures I 1 l5 /1 l\ A J t i i :3 J L l I g s] I 4 I l; i k (I PATENTEDJUNZSIBH INVENTORS WALTER PL OEGER, JR. JOHN w. H. BISHOP A TTORNEYS- 1 PRINTING RIBBON SPOOL The present invention is directed to a printing ribbon spool and method whereby a printing ribbon wound around the spool is replenished with ink to maintain consistency of ink density. The present invention is particularly adapted for use in connection with Teletype ribbons. Teletype or other slave type machine ribbons have a useful life of about 24 to 48 hours. Initially, the

Teletype ribbons print too dark. After about 24 hours of use, the Teletype ribbons print too lightly and have to be replaced.

I-Ieretofore, the printing ribbon spools on a Teletype printer such as a Teletype Corporation Model 28 Teletype printer, are carried on a vertical ribbon spool post whichhas a pivotable toggle at the top. When the spool is mounted on the post, the toggle is pivoted from an axial positionto a radial position so that it acts as a stop shoulder against which the upper surface of the spool contacts. However, the platform which carries the spool vibrates to a substantial extent, notwithstanding the aforesaid toggle stop shoulder. The spools of the present invention use a magnet to prevent such vibration.

The present invention solves the above-mentioned disadvantages in connection with Teletype printing ribbons and has other advantages. The present invention has a life span of approximately 6 weeks or longer instead of the usual 24 to 48 hours. At the same time, the present invention provides a spooled ribbon wherein the ribbon writes with a constant density from the beginning to the end of its life span. Further, the present invention utilizesa printing ribbon which is substantially shorter than that on a conventional Teletype machine. A conventional Teletype machine has a ribbon whose length is about twelve yards as compared with the present invention wherein the ribbon has a length of about I to '2 yards.

In accordance with the present invention, ink is withdrawn from a reservoir by capillary action using a wick of compressible material having one end communicating with said reservoir by way of an opening substantially smaller in dimensions than the transverse dimensions of said wick in its uncompressed state. Exceptfor said wick opening, the reservoir is hermetically sealed. Ink is transferred from the wick to a pad and from the pad to a printing ribbon by contact between the pad and an extreme side edge of the ribbon only during rel- I ative movement'betwen the'pad and ribbon.

Spools in accordance with the present invention are preferably utilized in pairs with each end of a ribbon secured to one of the spools. The terminal end portion comprising about two inches at each end of the ribbon is either of reduced width or ink impermeable so as to prevent ink build-up in said terminal portion from which ink is never withdrawn during operation. It is desirable to prevent ink on said terminal portion from being transmitted to the hub of the spool. A grommet is preferably secured to each ribbon end portion to effect reversing the spools in a conventional manner on a Teletype printer. While the present invention is particularly adapted for use on Teletype printers, it has wide application to other types of printing ribbons in a variety of types of printing equipment wherein long life and uniform density of printing are desired.

It is an object of the present invention to provide a novel apparatus for replenishing ink in a printing ribcontactbetween a source of ink and a side edge of the ribbon during relative movement between said source and the ribbon.

It is another object of the present invention to provide a printing ribbon spool having long life, uniform printing density during its life span, while utilizing a ribbon which is substantially shorter than those utilized heretofore.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood,however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a perspective view of a pair of spools in accordance with the present invention;

FIG. 2 is a sectional view taken along the line 22 in FIG. 1, but on an enlarged scale.

FIG. 3 is a sectional view taken along the line 33 in FIG. 2, but on an enlarged scale.

FIG 4 is a partial sectional view, similar to FIG. 2, but showing another embodiment of the. present invention.

Referring to the drawing in detail, wherein like nu-' merals indicate'like elements, there is shown in FIG. 1 a pair of printing ribbon spools in accordance with the present invention, each designated generally as 10.

The spool 10 has a body which includes a circular hub 12 having a radially outwardly directed flange 14 at one end and a radially outwardly directed flange 16 at its other end. The flanges l4 and 16 are spaced from one another and parallel to one another. However, flange 16 has an inturned end 15 projecting toward flange 14. Flanges l4 and 16 are of the same diameter. The flange 14 is integral with the side wall 19 and flange 16 is integral with stepped side wall 18.

The hub 12 is preferably provided with flats when being utilized on a Teletype printer. These flats are directly opposite one another. One of the flats serves to provide an acceptable surface for attachment, in any convenient manner such as by ultrasonic welding, to one end of an inked ribbon. The other flat is utilized to provide take-up space for the metal reversing eyelet which effects reversing of the ribbon on the Teletype printer. The terminal end portion of the ribbon constituting a length at least equal to the'circumference of the hub 12 'iseither of reduced width or rendered ink impregnable, such as by use of an ink impervious plastic shield, so as to prevent ink from accumulating in said terminal end portion.

The hub 12 has a third flange 20 which extends radially outwardly. The length of flange 20 in a radial direction is substantially less than the radial length of flanges l4 and 16. Further, flange 20 as shown more clearly in FIG. 2 is substantially closer to flange 16. The radial length of flange 20 exceeds the radial thickness of ribbon which will accumulate on a fully wound spool. A highly absorbent annular felt pad 22, which is readily deformable and to some extent compressible, is supported by the flange 20 and projects downwardly between the in-turned end 15 on the flange l6 and the outer periphery of flange 20. Thus, a portion 23 of the felt pad 22 is exposed and faces flange 14.

a The spool body includes a core 24 which is hollow and adapted to receive a mounting post. Core 24 has a concentric and enlarged diameter portion 26 within which is fixedly secured a driver 28.

The driver 28 is preferably a plastic annular member impregnated with magnetizable material. Driver 28 is force-fit or otherwise secured to the enlarged diameter portion 26. If desired, driver 28 may be adhesively secured to the enlarged diameter portion 26. Driver 28 is provided with one or more holes 30 to effect rotation of the spool about the longitudinal axis of core 24.

The spool body is preferably made in two pieces from an ink impervious lightweight material such as a polymer plastic. A suitable polymer for the body would be Celcon, which is a commercially available high crystalline acetal copolymer based on trioxane. One body portion is comprised of the hub 12, flange 14, wall 19, portion 26, and core 24. The other body portion is comprised of wall 18 and flange 16. The side edge portion of hub 12 adjacent wall 18 is preferably hermetically sealed thereto in any convenient manner such as by use of ultrasonic welding, adhesives, and the like. If desired, the core 24 could be extended and similarly sealed to wall 18.

Thus, the spool body includes an annular sealed chamber 33 defined at its inner periphery by core 24 and portion 26. The outer periphery of the chamber 33 is defined by the hub 12. Within the sealed chamber 33, there is provided a sealed ink reservoir. In the preferred embodiment, the sealed ink reservoir includes a carrier such as an absorbent, deformable felt pad 34 impregnated with ink.

At least one wick extends from pad 22 to the sealed ink reservoir. As illustrated, a pair of diametrically opposed wicks 38 and 39 is provided with each wick in contact with pad 34. Pad 22 partially compresses the exposed portion of the wicks supported by flange 20.

Each of the wicks 38 and 39 extends through a discrete hole 36 in the hub 12. The diameter of the hole 36 is significant in terms of the diameter of the wick. The diameter of hole 36 should be approximately 80 percent of the diameter of the wicks in their uncompressed state. Using a wick having a nominal diameter of one-eighth of an inch, optimum results have been obtained using holes 36 having a diameter of 0.099 inches. Except for the wick holes, the chamber 33 is hermetically sealed.

With a spool constructed as set forth above, we have observed that the portion of the wicks outside the casing 32 have a gray color indicating very little or no ink in the outer peripheral portion of the wick. An extremely small hole having a diameter of 0.004 inch was drilled through the wall 18 and immediately sealed with pressure-sensitive tape. As soon as the hole was uncovered by removing the tape, the exposed portion of the wicks immediately took on the color of the ink. Hence, we have found that it is important to have an ink reservoir which is hermetically sealed except for the wick hole.

Each wick has one end communicating with the ink reservoir and its other end in contact with the felt pad 22. Thus, each wick has a portion extending through a hole 36 in the hub 12 with its adajcent terminal end resting on the flange 20 beneath and in contact with the undersurface of pad 22.

A ribbon 42 having a length of approximately 1 to 2 yards extends between a pair of the spools 10. Each end portion of the ribbon 42 is secured to one of the spools 10 as described above. The width of the ribbon 42 is equal to or slightly greater than the distance from the exposed portion 23 of pad 22 to the flange 14. As pointed out above, the last several inches at each end of the ribbon 42 may be narrower by a distance of ap proximately one-eighth of an inch so as to avoid contact between the terminal end portion of the ribbon and portion 23 of pad 22. Alternatively, the terminal end portions of the ribbon 42 may be encased in a plastic ink-impervious sleeve. The ribbon 42 is preferably a five caliber nylon ribbon having a minimum thread count of about 274 threads per inch. Such a ribbon is conventionally used for printing ribbons on computers.

In FIG. 4, there is illustrated a second embodiment of the present invention designated generally as 10. The printing ribbon spool 10' is identical with spool 10 except as will be made clear hereinafter. Thus, in spool 10, the chamber 33 contains a hermetically sealed casing 32 filled with ink. Casing 32 has a hole through which wick 38 extends and which is of the same dimensions as hole 36. Otherwise, the embodiments are identical.

The spool 10 may be assembled as follows:

The body may be injection molded in two pieces as described above. The driver 28 may be attached in the portion 26 when desired during the initial assembly or during late stages in the assembly.

Before introducing the reservoir into the spool body, the wicks are threaded or otherwise forced through the holes 36 until they assume the disposition shown in FIG. 2, or equivalent disposition such as the wicks extending to the wall 19. Thereafter, the free or exposed end portions of the wicks may be extended through the holes 36 in the hub 12.

The uninked pad 22 is placed in position overlying the flange 20 with the inner periphery of pad 22 in contact with the outer periphery of hub 12. The impregnated pad 34 is introduced into chamber 33. For ease of handling, pad 34 may be encased in a sleeve at one end portion wherein thesleeve would not contact the wick." Thereafter, the wall 18 is juxtaposed to the other spool body portion and sealed thereto by the use of ink impervious adhesives or ultrasonic welding. During this step the portions of the wicks on flange 20 and to some extent the pad 22 are compressed. In this manner, a spool body is produced which cannot be reused after the ink reservoir has been depleted. With the hermetically sealed spool and reservoir provided in this manner, with no moving parts, there is no occasion for a user to tamper with the contents thereof.

We do not know and cannot explain how or why the invention works with any degree of certainty. lt is our belief that the use of a hole such as hole 36 through which the wick extends is an important feature of the invention. In this regard, the diameter of hole 36 must be substantially less than the diameter of the wick in its uncompressed state. As pointed out above, excellent results have been obtained wherein the diameter of the hole 36 is approximately percent of the diameter of the wick in its uncompressed state.

Test results have indicated that the spooled ribbon of the present invention has a leakproof and exceptionally long storage shelf life. It is believed that the wick does not continuously transfer ink to the pad except when the pad 22 is transferring ink to the ribbon 42.

When the spool is in use, the ribbon 42 appears to wiggle or flex the exposed portion 23 of pad 22. During winding, the ribbon 42 tends to flex exposed portion 23 of pad 22 radially inwardly. During unwinding, the ribbon 42 flexes portion 23 radially outwardly. It appears that this action primes or pumps the flow of ink through the wicks. When the spool is not in use, the capillary flow of ink along the wicks stops after a short period of time.

When assembling the spool 10, it is not necessary for pad 22 to be pre-inked. After about 6-8 hours of shelf life, pad 22 will become inked to a certain point and thereafter absorbs no further ink from the wicks. This seems to indicate that a balance has been achieved. If the newly assembled spool is put on a machine with pad 22 still dry, the pad 22 starts transferring ink to the ribbon in less than 3 hours and will be wetter than the pad of a spool which has been sitting on a shelf for 6-8 hours.

During usage, the driver 28 magnetically exerts sufficient force to hold the spool downwardly so as to avoid the vibration to which such spools have been subjected heretofore in certain types of Teletype printers. The minimizing of vibration has a beneficial effect on proper tracking of the ribbon 42 and on the uniformity of the printing. One spool is rotated clockwise by projections entering into the holes 30 on each of the drivers, while the other spool is rotated counterclockwise.

During a single pass of the ribbon, ink will be replenished at the top edge of the ribbon 42 twice, that is, once during takeup and once during payout. As ink is withdrawn from the area on the ribbon which is hit by the key, the struck area will replenish itself by drawing through capillary action from an adjacent area thereabove. The bottom edge portion of the ribbon below the key-strike area remains relatively dry. By continuing the feeding of the top area of the ribbon due to contact between the side edge of the ribbon 42 and the portion 23 of felt pad 22, the area struck by keys on the ribbon 42 will always have a supply of ink thereabove to draw from.

While the above-described embodiments utilize one or more wicks which are round, it will be readily apparent that wicks of other cross-sectional configurations may be utilized. If so, the ratio of transverse dimensions of the wicks and the holes which communicate the wicks with the reservoir should be maintained.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

We claim:

1. A set of spools for replenishing ink in a printing ribbon comprising:

a. first and second annular spool bodies,

b. a printing ribbon having a length of about one to two yards, c. each body having a hub and a pair of spaced radially outwardly directed flanges, said hub being between said flanges and having said ribbon wound therearound, an annular pad of absorbent deformable material supported at one of said flanges in a position spaced radially outwardly from the hub so that an exposed portion of the pad will have contact with a side edge of at least a portion of said ribbon, a reservoir supported by the body, a wick of compressible material extending between said pad and reservoir for transferring ink from the reservoir to the pad by capillary action, and means defining at least one access opening to said reservoir through which said wick extends and which is smaller in transverse dimensions of said wick in its uncompressed state, said reservoir having no access opening other than an opening through which a wick extends,

d. one end of said ribbon being attached to the hub of the first body, the other end of the ribbon being attached to the hub of the second body,

e. whereby ink may be transferred from the reservoirs to the pads and then to the ribbon by contact between the pads and the side edge of the ribbon as a result of relative movement between the pads and the ribbon.

2. A spool for replenishing ink in a printing ribbon comprising an annular spool body having a hub and a pair of spaced radially outwardly directed flanges, said hub being between said flanges and adapted to have a ribbon wound therearound, an annular pad of absorbent deformable material supported at one of said flanges in a position so that an exposed portion of the pad will have contact with a side edge of at least a portion of the ribbon to be wound on the hub, a reservoir supported by said body, a wick of compressible material extending between said pad and reservoir for transferring ink from the reservoir to the pad by capillary action, and means defining at least one access opening to said reservoir through which said wick extends and which is smaller in transverse dimensions than said wick in its uncompressed state, said reservoir having no access opening other than an opening through which a wick extends, whereby transferral of ink from said reservoir to said pad is initiated only by flexing of said exposed portion of said pad.

3. A spool in accordance with claim 2 wherein said reservoir is located within said hub.

4. A spool in accordance with claim 2 wherein said reservoir includes ink impregnated in a carrier disposed within said hub. f

5. A spool in accordance with claim 2 wherein said spool body is of non-magnetic material and includes a centrally disposed core having a driver of magnetic material secured thereto to facilitate rotating the spool body about the longitudinal axis of the core, at least a portion of said core being hollow so that it may receive a spindle.

6. A spool in accordance with claim 2 including a pair of said wicks each having one end communicating with said reservoir by a separate access opening and another end in contact with said pad.

7. A spool in accordance with claim 2 wherein said means defining access to said reservoir is a hole having a diameter of approximately of the diameter of the wick in its uncompressed state.

8. A spool in accordance with claim 5 wherein said wick has a diameter of approximately one-eighth of an inch in its uncompressed state, and said hole having a diameter of 0.099 inch.

9. A spool in accordance with claim 2 wherein said hub has a third radially outwardly directed flange between said first and second flanges, said third flange being adjacent said one flange and having a radial pro- 8 jection which is less than the radial projection of said outer periphery of said third flange extends radially befirst flange so as to define an annular space between the d th t Y third flange and said one flange through which the exyon 6 Cu er periphery of the ribbon wound on {ht posed portion of said pad extends.

10. A spool in accordance with claim 9 wherein the 

1. A set of spools for replenishing ink in a printing ribbon comprising: a. first and second annular spool bodies, b. a printing ribbon having a length of about one to two yards, c. each body having a hub and a pair of spaced radially outwardly directed flanges, said hub being between said flanges and having said ribbon wound therearound, an annular pad of absorbent deformable material supported at one of said flanges in a position spaced radially outwardly from the hub so that an exposed portion of the pad will have contact with a side edge of at least a portion of said ribbon, a reservoir supported by the body, a wick of compressible material extending between said pad and reservoir for transferring ink from the reservoir to the pad by capillary action, and means defining at least one access opening to said reservoir through which said wick extends and which is smaller in transverse dimensions of said wick in its uncompressed state, said reservoir having no access opening other than an opening through which a wick extends, d. one end of said ribbon being attached to the hub of the first body, the other end of the ribbon being attached to the hub of the second body, e. whereby ink may be transferred from the reservoirs to the pads and then to the ribbon by contact between the pads and the side edge of the ribbon as a result of relative movement between the pads and the ribbon.
 2. A spool for replenishing ink in a printing ribbon comprising an annular spool body having a hub and a pair of spaced radially outwardly directed flanges, said hub being between said flanges and adapted to have a ribbon wound therearound, an annular pad of absorbent deformable material supported at one of said flanges in a position so that an exposed portion of the pad will have contact with a side edge of at least a portion of the ribbon to be wound on the hub, a reservoir supported by said body, a wick of compressible material extending between said pad and reservoir for transferring ink from the reservoir to the pad by capillary action, and means defining at least one access opening to said reservoir through which said wick extends and which is smaller in transverse dimensionS than said wick in its uncompressed state, said reservoir having no access opening other than an opening through which a wick extends, whereby transferral of ink from said reservoir to said pad is initiated only by flexing of said exposed portion of said pad.
 3. A spool in accordance with claim 2 wherein said reservoir is located within said hub.
 4. A spool in accordance with claim 2 wherein said reservoir includes ink impregnated in a carrier disposed within said hub.
 5. A spool in accordance with claim 2 wherein said spool body is of non-magnetic material and includes a centrally disposed core having a driver of magnetic material secured thereto to facilitate rotating the spool body about the longitudinal axis of the core, at least a portion of said core being hollow so that it may receive a spindle.
 6. A spool in accordance with claim 2 including a pair of said wicks each having one end communicating with said reservoir by a separate access opening and another end in contact with said pad.
 7. A spool in accordance with claim 2 wherein said means defining access to said reservoir is a hole having a diameter of approximately 80% of the diameter of the wick in its uncompressed state.
 8. A spool in accordance with claim 5 wherein said wick has a diameter of approximately one-eighth of an inch in its uncompressed state, and said hole having a diameter of 0.099 inch.
 9. A spool in accordance with claim 2 wherein said hub has a third radially outwardly directed flange between said first and second flanges, said third flange being adjacent said one flange and having a radial projection which is less than the radial projection of said first flange so as to define an annular space between the third flange and said one flange through which the exposed portion of said pad extends.
 10. A spool in accordance with claim 9 wherein the outer periphery of said third flange extends radially beyond the outer periphery of the ribbon wound on the hub. 